Question: Khan.scratchpad.disable(); For every level Michael completes in his favorite game, he earns $640$ points. Michael already has $220$ points in the game and wants to end up with at least $2230$ points before he goes to bed. What is the minimum number of complete levels that Michael needs to complete to reach his goal?
To solve this, let's set up an expression to show how many points Michael will have after each level. Number of points $=$ $ $ Levels completed $\times$ Points per level $+$ Starting points Since Michael wants to have at least $2230$ points before going to bed, we can set up an inequality. Number of points $\geq 2230$ Levels completed $\times$ Points per level $+$ Starting points $\geq 2230$ We are solving for the number of levels to be completed, so let the number of levels be represented by the variable $x$ We can now plug in: $x \cdot 640 + 220 \geq 2230$ $ x \cdot 640 \geq 2230 - 220 $ $ x \cdot 640 \geq 2010 $ $x \geq \dfrac{2010}{640} \approx 3.14$ Since Michael won't get points unless he completes the entire level, we round $3.14$ up to $4$ Michael must complete at least 4 levels.